The energy finance director at the Institute of Energy, Economics and Financial Analysis said at this stage, the company does not have financial institutions willing to bankroll the project.

"Adani's Carmichael proposal has a multitude of obstacles to get into financial close," Tim Buckley said.

Mr Buckley, a critic of the Adani coal mine, argued the project was not viable and the energy landscape in India was changing dramatically.

In terms of the financial assurance for rehabilitation, Mr Buckley said Adani does not have to put up hard capital but needs to find a financial institution to go guarantor on the project.

"I think Adani is going to struggle to find anyone willing to go guarantor on a multi-billion-dollar, multi-decade rehabilitation liability."

Report offers 'very realistic assessment'

Dr Gavin Mudd, an associate professor at RMIT University's School of Engineering, said rehabilitation costs were often underestimated.

"If you look at mining in Australia we've often underestimated I think the true, full cost of rehabilitation. But I think we have also underestimated the standards the community are expecting," Dr Mudd said.

"The scale at which we are operating, or we're proposing projects now, is unprecedented and that's really what presents the challenge.

"I think this report is a very realistic assessment and I think the industry and government need to get past the historic practice of generally treating things like bonds and the cost of rehabilitation as very commercially sensitive."

Environment Minister Steven Miles previously said Adani would have to comply with the reforms.

"These reforms will apply to both existing and new operations so if a project like that one gets off the ground in the coming years these reforms will ensure that the state is protected, that we have sufficient financial assurance and that rehabilitation occurs progressively," Mr Miles said.